A technique that removes an oxide (scale) formed on the surface of steel strips by electrolyzing scale in solutions such as a neutral salt, a nitrate and a sulfate is known.
The Japanese patent Laid-open No. 3-56699 describes pumping an electrolyte to a steel strip submerged in the electrolyte from the hole of an electrolyte in order to prevent the steel strip from waving.
The Japanese patent Laid-open No.8-100299 describes spraying an electrolyte to a steel strip in the air in order to apply an electric current.